The present invention relates to a vehicle seat and is particularly applicable to the seat of an agricultural vehicle, such as a tractor.
Tractor operators sometimes use a joystick to control the position of an implement or ancillary equipment mounted on the tractors. The operator may need to move or swivel the seat while using the joystick, for example to keep sight of the implement being manipulated using the joystick, and for this reason it is convenient to mount the joystick on the seat so that it moves with the seat and always remains within easy reach of the operator.
Joysticks are known that operate electronically, these being in principle similar to the joystick used in playing computer games. Such joysticks are only required to move the tappings of two potentiometers and they can therefore be constructed as small units that are easily mounted on a seat. Furthermore, the wires leading to the potentiometers of such joysticks can readily be mounted neatly in the cab of the tractor.
The disadvantage of such joysticks is that they can only be used in conjunction with a complex and costly electronic implement control system which must additionally comprise such items as servo-motors, position sensors and a control circuit.
A more simple solution to allow remote control of the position of an implement is to use a mechanical joystick. Such a joystick is connected to the implement by means of Bowden cables and the mechanical effort for moving the implement is provided by the operator. In this way, the requirement for servo-motors and a control system is avoided.
Mounting mechanical joysticks on a vehicle seat presents difficulty because they are of necessity larger and bulkier than electronic joysticks and they would tend to inhibit access to the seat.
It is an object of the present invention to provide a vehicle, in particular a tractor, designed to eliminate the aforementioned drawbacks.
It is another object of this invention to mitigate the problem of seat access on a tractor when using a mechanical joystick.
According to the present invention, there is provided a vehicle seat for an operator in combination with a mechanical joystick for operating ancillary equipment of the vehicle, wherein the joystick is pivotably mounted on the seat for movement between an active position in which the joystick may be manipulated by a seated operator and a stowed position in which access to the seat is unencumbered by the joystick.
By pivotably mounting the joystick on the seat, the invention enables it to be conveniently stowed away when not in use or when the operator is entering the vehicle.
It is common in a mechanical joystick to provide a control button for locking the joystick in position to prevent accidental movement of the implement controlled by the joystick. In a preferred embodiment of the invention, the joystick is provided with such a control button for enabling and disabling operation of the joystick and the control button is mechanically coupled to the seat in such a manner that the joystick is automatically disabled when the joystick is in the stowed position. This may conveniently be achieved by coupling the control button to the seat by means of a Bowden cable.
Advantageously, each of the Bowden cables connecting the joystick to the controlled implement includes slack to permit the seat and the joystick to move freely. To prevent the cables, especially when not taut, from presenting an obstacle or a hazard, means may be provided for constraining the slack sections of the Bowden cables. For example, the slack may be coiled or looped and guided in the vehicle cab in such a manner as to stack away safely and neatly.
In the preferred embodiment of the invention, the joystick is mounted on the seat by means of a bracket having two arms at an angle to one another, the first arm being pivotable at its free end relative to the seat and the second arm supporting the joystick at its free end. If the first arm is pivotably mounted to the seat at a point higher than the base of the seat and the second arm, when in the active position, lies below and extends parallel to the top surface of the base of the seat, then as the bracket is pivoted towards the stowed position, the joystick moves towards the seat back at the same time as it is being lowered.
If the seat is provided with an arm rest, then the first arm of the bracket is most conveniently pivoted at a point that is just below the arm rest.
It is desirable to be able to lock the bracket in any position and this may be achieved by providing an arcuate slot in the bracket to receive a locking bolt that engages in the base of the seat.
It is advantageous in a mechanical joystick to provide as long a control rod as possible in order to reduce the force that must be exerted by the operator when controlling the implement. To permit the use of a long control rod while without interfering with the stowing away of the joystick, it is preferred for the joystick to comprise a telescopically extendable control rod.
These and other objects, features and advantages are accomplished according to the instant invention by providing a vehicle seat for an operator is disclosed in combination with a mechanical joystick for operating ancillary equipment of the vehicle. The joystick is pivotably mounted on the seat for movement between an active position in which the joystick may be manipulated by a seated operator and a stowed position in which access to the seat is unencumbered by the joystick.